1. Field of the Invention
This invention relates generally to heating apparatus, and, more specifically, to a passive solar heating apparatus particularly suited to use in a swimming pool as a pool heater.
2. Description of the Prior Art
In the past, swimming has become a preferred form of healthful recreation for a substantial portion of the populace. For convenience, many people have installed swimming pools at home. Since comfort required that the temperature of the water in the pool not fall substantially below 70 degrees Farenheit, people were generally faced with a choice between using the swimming pool only in the warm summer months, or installing a pool heater to heat the water to substantially extend the swimming season. Typically, such pool heaters utilized electricity or natural gas as an energy source for the required heat. While such energy sources were once "penny cheap," the cost of both electricity or natural gas have risen steadily. Since heating a swimming pool required a substantial energy input, that rise in the cost of energy has turned the operation of such pool heaters into an expensive luxury.
Another approach to heating the water in a swimming pool has been to utilize the free energy radiating from the sun. While the actual energy input required to operate a solar heater is minimal, the hardware required for such an installation has been expensive. Additionally, installation of such a solar heater apparatus in a pool not already equipped with a heater device required extensive reworking of the pool plumbing, generally rendering the addition of such a solar heater financially impractical. A need existed for a low-cost pool heater apparatus which required neither expensive energy inputs nor extensive modification of an existing pool for installation.